Jksw
“In
November 1894, the Indian physicist, Jagadish Chandra Bose,
demonstrated publicly the use of radio waves in Calcutta, but he was not interested in patenting
his work.[85]
Bose ignited gunpowder and
rang a bell at a distance using electromagnetic waves,[86] confirming that
communication signals can be sent without using wires. He sent and received
radio waves over distance but did not commercially exploit this achievement.
Bose
demonstrated the ability of the electric rays to travel from the lecture room,
and through an intervening room and passage, to a third room 75 feet
(23 m) distant from the radiator, thus passing through three solid walls
on the way, as well as the body of the chairman (who happened to be the
Lieutenant-Governor).
The
receiver at this distance still had energy enough to make a contact which set a
bell ringing, discharged a pistol, and exploded a miniature mine. To get this
result from his small radiator, Bose set up an apparatus which curiously
anticipated the lofty 'antennae' of modern wireless telegraphy— a circular
metal plate at the top of a pole, 20 feet (6.1 m) high, being put in
connection with the radiator and a similar one with the receiving apparatus.[87]
The
form of 'Coherer' devised by Professor Bose, and described by him at the end of
his paper 'On a new Electro Polariscope' allowed for the sensibility and
range to appear to leave little to be desired at the time.[87] In 1896, the Daily Chronicle of
England reported on his UHF experiments: "The inventor (J.C. Bose) has
transmitted signals to a distance of nearly a mile and herein lies the first
and obvious and exceedingly valuable application of this new theoretical
marvel."
After
Bose's Friday Evening Discourses at the Royal Institution, The
Electric Engineer expressed 'surprise that no secret was at any time made as to
its construction, so that it has been open to all the world to adopt it for
practical and possibly money-making purposes.' Bose was sometimes,
and not unnaturally, criticised as unpractical for making no profit from his
inventions.[87]
In
1899, Bose announced the development of an "iron-mercury-iron coherer with telephone detector" in a paper presented at
the Royal Society, London.[88] Later he received U.S. Patent
755,840, "Detector for electrical disturbances"
(1904), for a specific electromagnetic receiver. Bose would continue research
and made other contributions to the development of radio.[89]
